Rebels seized control of a border crossing on the frontier with Turkey on Wednesday, pulling down the Syrian flag and sending a stream of jubilant people pouring across the border into Turkey.
An Associated Press reporter at the scene Wednesday said people were moving freely across the Tal Abyad crossing, crawling under barbed wire. Some appeared to be wounded.
"I am a free Syrian!" one man shouted, throwing his hands in the air.
Syria's rebels control several other border crossings into Turkey but Wednesday's capture of the Tal Abyad post is believed to be the first time they have taken the border area in the northern province of Raqqa.
Taking control of border crossings helps the opposition ferry supplies into Syria and carve out an area of control, which is key as the rebels try to tip the balance in the civil war.
Wednesday's takeover comes after a day of fierce clashes as rebels and regime forces fought for control of the Tal Abyad crossing.
Turkey's private Dogan news agency said earlier Wednesday that the rebels surrounded the customs building and engaged in an intense fire fight with Syrian sharp-shooters positioned at the building. Several people were wounded in the battles and were taken to Turkey for treatment, the report said.
Civilians escaping the violence reported that several people were killed in fighting around Tal Abyad, Dogan reported.
The 18-month conflict between the regime of President Bashar Assad and his opponents began with peaceful protests that were attacked by government security forces, and has since evolved into a civil war. Activists say at least 23,000 people have died, many of them civilians who fell victim to the regime onslaught, although rebel factions have also been accused of summary executions and other abuses.
Also Wednesday, Amnesty International said the Syrian government has carried out indiscriminate air bombardments and artillery strikes on residential areas that do not target opposition fighters or military objectives, and instead appear aimed solely at punishing civilians seen as sympathetic to rebel forces.
Much of the recent fighting has centered on the contested city of Aleppo, but the London-based group said hundreds of civilians in other parts of northern and central Syria have been killed or wounded in recent weeks, many of them children, in attacks that struck people in their homes, in the street or while trying to take shelter from the bombings.
The conclusions were published in an Amnesty report that followed a visit to Syria by senior crisis researcher Donatella Rovera, who traveled to 26 towns and villages in the Jabal al-Zawiya area and other parts of the northern Idlib and north Hama regions between Aug. 31 and Sept. 11.